1. Field of the Invention
The present invention relates to an aluminum-based alloy for use in a wide range of applications such as in a structural material for aircraft, vehicles, and ships, and for engine parts. In addition, the present invention may be employed in sashes, roofing materials, and exterior materials for use in construction, or as material for use in marine equipment, nuclear reactors, and the like.
2. Description of Related Art
As prior art aluminum-based alloys, alloys incorporating various components such as Al--Cu, Al--Si, Al--Mg, Al--Cu--Si, Al--Cu--Mg, and Al--Zn--Mg are known. In all of the aforementioned, superior anti-corrosive properties are obtained at a light weight, and thus the aforementioned alloys are being widely used as structural material for machines in vehicles, ships, and aircraft, in addition to being employed in sashes, roofing materials, exterior materials for use in construction, structural material for use in LNG tanks, and the like.
However, the prior art aluminum-based alloys generally exhibit disadvantages such as a low hardness and poor heat resistance when compared to material incorporating Fe. In addition, although some materials have incorporated elements such as Cu, Mg, and Zn for increased hardness, disadvantages remain such as low anti-corrosive properties.
On the other hand, recently, experiments have been conducted in which a fine metallographic structure of aluminum-based alloys is obtained by means of performing quick-quench solidification from a liquid-melt state, resulting in the production of superior mechanical strength and anti-corrosive properties.
In Japanese Patent Application, First Publication No. 1-275732, an aluminum-based alloy comprising a composition AlM.sub.1 X with a special composition ratio (wherein M.sub.1 represents an element such as V, Cr, Mn, Fe, Co, Ni, Cu, Zr and the like, and X represents a rare earth element such as La, Ce, Sm, and Nd, or an element such as Y, Nb, Ta, Mm (misch metal) and the like), and having an amorphous or a combined amorphous/fine crystalline structure, is disclosed.
This aluminum-based alloy can be utilized as material with a high hardness, high strength, high electrical resistance, anti-abrasion properties, or as soldering material. In addition, the disclosed aluminum-based alloy has a superior heat resistance, and may undergo extruding or press processing by utilizing he superplastic phenomenon observed near crystallization temperatures.
However, the aforementioned aluminum-based alloy is disadvantageous in that high costs result from the incorporation of large amounts of expensive rare earth elements and/or metal elements with a high activity such as Y. Namely, in addition to the aforementioned use of expensive raw materials, problems also arise such as increased consumption and labor costs due to the large scale of the manufacturing facilities required to treat materials with high activities. Furthermore, this aluminum-based alloy having the aforementioned composition tends to display insufficient resistance to oxidation and corrosion.
U.S. Pat. No. 5,419,789 discloses an aluminum-based alloy having high strength and heat resistance which has a composition represented by the general formula Al.sub.bal Ni.sub.a XbM.sub.c, wherein X is one or two elements selected from the group consisting of Fe and Co; M is at least one element selected from the group consisting of Cr, Mn, Mo, Ta, and W; a, b, and c are, in atomic percentages, 5.ltoreq.a.ltoreq.10, 0.5.ltoreq.b.ltoreq.10, and 0.1.ltoreq.c.ltoreq.5. This aluminum-based alloy has a structure in which quasicrystals are homogeneously dispersed in a matrix composed of aluminum or a supersaturated solid solution of aluminum.
Although the aluminum-based alloy according to U.S. Pat. No. 5,419,789 may have high strength, high hardness, and high heat resistance, it does not have a sufficient ductility and toughness so as to be processible into a structural material.